Zipties are wonderful. An art form when required. Not quite modding, but so much more pleasant than those annoying spring steel clips that seem to be designed to sabotage the elegant profile of the great air coolers.
For push/pull fan mounting, zipties are simpler, cleaner and just plain more sexy than two sets of finger traps.
Here's the ZipTie Screw thread created by, yes, ehume, fan mounting guru. It's rumoured he once mounted 65 fans on a Megahalems. Using only time, patience and zipties.
How clean is that? No bulging out, look-at-me, look-at-me steel eyesores that can pollute the sleek edge of a graceful fin stack.